defmodule DaProductApp.Repo.Migrations.CreateTransactionEventChain do
  use Ecto.Migration

  def change do
    create table(:transaction_event_chain) do
      add :transaction_id, :bigint, null: false
      add :event_type, :string, null: false
      add :event_ref_table, :string, null: false
      add :event_ref_id, :bigint
      add :prev_event_id, :bigint
      add :payload, :text
      timestamps()
    end

    create index(:transaction_event_chain, [:transaction_id])
    create index(:transaction_event_chain, [:transaction_id, :inserted_at])
    create index(:transaction_event_chain, [:prev_event_id])

    create constraint(:transaction_event_chain, :transaction_fk, 
             check: "transaction_id IS NOT NULL")
  end
end